Impact implement



J. M. CROWE IMPACT IMPLEMENT Filed Jan. 28, 1955 Patented May 26, 1936 warren srArss PATENT @FFIQE IMPACT IMPLEMENT John Marshall Crowe, Govington, Ky. Application January 28, 1935, Serial No. 3,813

6 Claims.

The present invention relates to an impact or percussion implement of the general type commonly used for cutting through concrete, stone,

and various other substances, and for hammering undesirable vibration than any similar device heretofore known.

Another object of the invention is to provide specifically for elimination of breakage, undue Wear, and premature replacement of the motive means and the main shaft of the impact or percussion implement.

A further object of the invention is to provide for a more effective placement and delivery of blows by the hammer elements upon the anvil, tool end, or tool holder of the device, resulting in a more forceful and powerful operation with a minimum of destructive wear.

The foregoing and other objects are attained by the means described herein and disclosed in the accompanying drawing, in which:

Fig. 1 is a vertical sectional view showing the device of the invention with one of its hammer elements or rollers in striking position upon the anvil or tool holder.

Fig. 2 is a fragmental cross-sectional view taken on line 2-2 of Fig. 1,

Fig. 3 is a fragmental cross-sectional view taken on line 3t of Fig. 2.

Fig. 4 is a cross-sectional view, similar to Fig. 2 but showing the hammer'elements or rollers in the free or neutral position, remote from the anvil ortool holder.

Fig. 5 is an elevational view of the hammer unit, looking at Fig. 4 from right to left, the casing or housing being omitted.

Fig. 6 is a plan view of a carriage part for the hammer members.

Tools or implements of the character herein referred to have always presented perplexing problems concerning proper balancing of the moving parts thereof and problems concerning elimination of premature breakage and replacement of parts, as Well as undue wear, due to the rapid and severe delivery of hammer blows upon the tool or the anvil which transmits the blows to the tool. Asstated above, one of the objects of the present invention is to provide an impact or percussion implement with a novel arrangement of means whereby the premature breakage, replacement and wear are reduced to a minimum, While at the same time the undesirable vibrations which are transmitted to the workmans body are minimized to an appreciable extent. The objections above noted are overcome by means of the structure described below.

In the drawing, the character 7! indicates a case or housing which includes a socket or means 8 for the attachment of a handle 9. At an opposite side of the case or housing there is provided a second socket or sleeve I which is adapted to support a bearing element l 2 in which may reciprocate an anvil, tool, tool holder or other like member indicated by the character l3. The case also carries a series of anti-frictional bearings I l, l5 and I6 adapted to rotatably support a main shaft or power-actuated driving element l1. With reference to Fig. 1, it may be observed that all of the mechanism disposed at the right of the partition member it represents a motor I 9 adapted to have electrical power carried thereto by means of the cable or group of conductors 20. That portion of the driving element i l which is located between the bearings i i and 15, carries a pair of circular plate-like elements 2| and 22 which cooperate to provide a carriage or cage for supporting a plurality of hammer members which direct a rapid succession of blows upon the anvil or tool E3. The members 2i and 22 which. constitute the carriage or cage, may be keyed or otherwise fixed to the shaft ll for rotation therewith, as indicated at 23. The carriage 2 l--22 maybe further held in position by means .of a nut 24 which is screwed onto the end of the driving element so as to maintain the member 22 in abutment upon a shoulder 25 of the driving element or shaft ill. The nut 24 may be locked by means of a cotter pin or other suitable locking means 26.

As is most clearly indicated in Figs. 4 and 5, the members 2| and 22 abut one another along a line 21, and each of the said members are milled out or so shaped as to provide the ways or slots 28 and 29 which, when in registration, substantially enclose the pair of hammer members or weighted blocks 30 and 3!. It should be observed that the hammer elements are provided at their innermost portions with pairs of perforated ears or extensions 32-32 and 33-33. The cutaway portion 3 1 and 35 between the ears of hammer members 31! and 39, respectively, are so located and positioned as to be always free of contacting relationship with the driving element or shaft It is noteworthy also that the space or way in which the hammer members are received (Figs. 2 and 4), is made considerably wider than the width of the hammer members, so that the hammer members may have both a radial shifting movement and a lateral shifting movement to a cocked or offset position as indicated in Fig. 2. The hammer members may momentarily assume the cooked or offset positions, or not, depending upon the amount of force the user applies to the tool by means of the handle bar or member 3. The provision of means for permitting the cooked or offset disposition of the hammer members is for the purpose of absorbing or dampening shocks or vibrations which would otherwise be transmitted fully to the housing and the handle member 9 under certain conditions of usage of the implement.

It is to be understood that the hammer members normally are extended radially of the shaft H by the action of centrifugal force generated by reason of rapid rotation of shaft when driven by the motor l9. Each of the hammer members may be provided with a roller 36 or its equivalent, the rollers being mounted upon shafts of bearings 31 and 38 located near the peripheries of the hammer members 3| and 30 respectively, so that the hammer members or blocks, when extended during rotation of the carriage 2|-22, will dispose the rollers in extended positions for striking the anvil or tool 13.

Means separate from the shaft H are provided for limiting the inward, outward and cocking movements of the hammer members 36 and 3|. Said means may comprise suitable coupling members which may be in the nature of radially disposed stops or abutments 39 and 40 fixed to the carriage or cage, and extending into the ways 28 and 29 toward the shaft said stops or abutments being loosely received in pairs of transverse channels or recesses -45 and 46-46 milled or otherwise formed in the ears or extensions of the hammer members. In the preferred embodiment, the stops or abutments 39 and 40, are pinned or otherwise secured within relatively shallow slots or seats 41 and 48, respectively, formed in the respective complementary parts 22 and 2| of the rotating cage or carriage, so that each stop or abutment may cooperate with both hammer members or blocks 30 and 3|, as indicated by Fig. 3, to limit the movement of such hammer members or blocks. With reference to Fig. 6, it is to be understood that the stop or abutment which is not shown therein, (numbered 39 in Fig. 4), but which in the assembled device assumes a position opposite to the stop 40, is adapted to rest in a shallow seat 49 of disc or plate 2| to effect the relationship depicted by Fig. 3. The stop 43 of course has a like relationship with the opposed disc or plate 22, as will be understood.

The above mentioned loose coupling means between the carriage and the hammer members permits but limits the inward, outward and cocking movements of the hammer members during rotation of the shaft and carriage. The forces or shocks resulting from said movements of the hammer members therefore are not imparted directly to the shaft H, but are directed against the stops or abutments 39 and 43. Thus, the shaft cannot be cut, abraded, dented or otherwise injured by the rebound of the hammer members. From the foregoing, it must be evident that the rebound shocks are taken up by the stops or abutments 39 and 40, transmitted to the carriage 2l-22, and thence to the shaft through solid connections closely adjacent to the shaft-supporting bearings I4 and 55. Both of the members 2| and 22 cooperate in absorbing the shocks due to the fact that said members are connected together by means of two or more connecting means 42 which may be in the form of bolts or the like.

The relationship of the various elements as disclosed in Fig. 2, is the result of clock-wise rotation of the carriage 2| just as the lower-most roller 36 strikes the anvil or tool l3. The block or hammer member 3| has moved inwardly, or has rebounded due to the impact of the roller upon the tool or anvil I3, while at the same time the hammer member 3| has cocked itself and has thereby absorbed the greater portion of the rebound shock without transmitting such shock directly to the shaft H at the point 34. It will be noted that the adjacent stop or abutment 39 has limited the rebound of the hammer member, and that the other hammer member numbered 33, is fully extended by the action of centrifugal force, in readiness for a subsequent impact of its roller upon the tool or anvil l3. Under no conditions do the rollers 36 ride upon the interior of the case or housing I, wherefore there are no frictional losses sustained due to case or housing interference. The striking face of the anvil or tool I3 is rendered properly receptive of the roller impact, by reason of the fact that the tool or anvil axis is offset slightly in a direction counter to the direction of rotation of the carriage 2| (Fig. 2). Upon movement of the carriage or cage from the Fig. 2 position to the Fig. 4 position centrifugal force maintains the hammer members in extended positions, as shown in Fig. 4, and continued rotation of the carriage causes the roller of hammer member 33 to strike the anvil or tool in the manner of the Fig. 2 illustration.

It is to be understood that the stops or abutments which limit the shifting movements of the hammer members, may be carried by one or both of the hammer members instead of by the car riage, in which case the carriage would be provided with enlarged openings such as 45 to cooperate in providing the loose connection or coupling above referred to.

The character 44 (Fig. 1) indicates a cap or retainer which acts upon the shoulder 46 of the anvil or tool for maintaining the anvil or tool in connected relationship with the case or housing I.

It is to be understood that various modifications and changes in the structural details of the device may be made, within the scope of the appended claims, without departing from the spirit of the invention.

What is claimed is:

1. In an impact or percussion implement, the combination of a power actuated rotatable driving element, a carriage having a radially disposed way and supported for rotation with said driving element, an anvil mounted for reciprocatory movement toward and from the carriage, a pair of opposed hammer members for striking the anvil, said hammer members being considerably narrower than the way of the carriage and disposed therein for shifting movement both longitudinally and laterally of the way, a pair of spaced ears on each hammer member, which ears extend about the driving element in opposite directions, a coupling means carried by each ear, cooperative coupling means carried by the carriage and providing a loose connection of the carriage with the ears of the hammer members whereby the hammer members are limited in their aforesaid shifting movement, precluding rebound of the hammer members directly against the driving element.

2. In an impact or percussion implement, the combination of a power actuated rotatable driving element, a carriage supported for rotation with said driving element, an anvil mounted for reciprocatory movement toward and from the carriage, a pair of opposed hammer members for striking the anvil as the driving element is rotated, a pair of spaced ears on each hammer member, which ears extend about the driving element and overlap in opposite directions, the ears being so spaced and proportioned as to preclude contact of the hammer members upon the driving element, and means fixed upon the carriage and engaging the overlapping ears with a loose fit to permit and limit shifting movements of the hammer members both radially and rotationally in a plane parallel to the carriage.

3. In an impact or percussion implement, the combination of a power actuated rotatable driving element, a bi-part carriage having a radially disposed way and supported for rotation with said driving element, an anvil mounted for reciprocatory movement toward and from the carriage, a pair of opposed hammer members for striking the anvil, said hammer members being considerably narrower than the way of the carriage and disposed therein for shifting movement both longitudinally and laterally of the way, a pair of spaced ears on each hammer member, the pairs of ears extending about the driving element in opposite directions, coupling means carried by each ear, cooperative coupling means carried by the carriage and providing a loose connection of the carriage with the ears of the hammer members whereby the hammer members are limited in their aforesaid shifting movement, to preclude rebound of the hammer members directly against the driving element, the coupling means of the carriage comprising a radially disposed stop on each of the carriage parts.

4. In an impact or percussion implement, the combination of a power rotated driving element, a carriage mounted upon the driving element for rotation therewith, said carriage comprising a pair of discs having formed between them a radial way, an anvil, a pair of opposed hammer mem bers of a width sufficiently narrower than the width of the radial way to allow for a cooking movement of the hammer members in the said way, while at the same time the hammer members have a longitudinal sliding movement in said way toward the anvil, means including stops carried by the carriage for limiting the movement 5 of the hammer members in the carriage way, and striking rollers rotatably supported by the hammer members with a portion of the peripheries of said rollers extending from the hammer members to engage the anvil.

5. In an impact or percussion implement, the combination of a power rotated driving element,

a carriage mounted upon the driving element for rotation therewith, said carriage comprising a pair of complementary discs each having formed therein a radial way, said ways cooperating to guide a pair of hammer blocks, an anvil, a pair of opposed hammer blocks of a width sufficiently narrower than the width of the radial ways to allow for both a cocking movement and a longitudinal movement of the hammer blocks in the ways relative to the anvil, a stop carried by each disc and mounted to extend transversely into the ways in the path of movement of said hammer blocks, and means on the blocks to cooperate with the transverse stops for limiting movement of the hammer blocks lengthwise of the radial ways of the carriage discs.

6. In an impact or percussion implement, the combination of a power rotated driving element, a carriage mounted upon the driving element for rotation therewith, said carriage comprising a pair of complementary discs each having formed therein a radial way, said ways cooperating to guide a pair of hammer blocks, an anvil, a pair of opposed hammer blocks of a Width sufiiciently narrower than the width of the radial ways to allow for both a cocking movement and a longitudinal movement of the hammer blocks in the ways relative to the anvil, a stop carried by each disc and mounted to extend transversely into the ways in the path of movement of said hammer blocks, and means on the blocks to cooperate with the transverse stops for limiting movement of the hammer blocks lengthwise of the radial ways of the carriage discs, a striking roller on each hammer block, and means for rotatably supporting said rollers with a portion of their peripheries extended beyond the blocks to contact the anvil upon rotation of the carriage.

JOHN MARSHALL CROWE. 

